In constructing various electromechanical devices there is frequently a need to transmit power and/or electrical signals from a stationary structure to a rotating structure. One well known example is a radar antenna that continuously rotates through three hundred and sixty degrees of motion. A special type of electromechanical connection is required in such cases, which is most often referred to as a “slip ring”, but it may also be called a rotary electrical joint, collector or electric swivel. Any electromechanical system that requires unrestrained intermittent or continuous rotation while also transmitting power and/or data can utilize a slip ring to great advantage. Typically in a slip ring a plurality of resilient, elongated metal or carbon conductors contact and slide over corresponding conductive contact rings. See for example U.S. Pat. No. 6,611,661 granted Aug. 26, 2003 of Buck. The design of a slip ring can improve mechanical performance of the system, and improve reliability by eliminating dangling wires that can break or become tangled. Fiber optic rotary joints (FORJ's) have also been specially designed for high-speed data transfer in EMI sensitive environments. While slip rings have been widely used for decades, little attention has been paid to improving their simplicity and versatility. Therefore, it would be desirable to provide an improved slip ring assembly that is more functional, cost-effective and reliable, and has improved features of use and operation.
In accordance with the present invention, a slip ring assembly includes a plurality of contact rings and means for supporting the contact rings in spaced relation about a common axis. A housing is located adjacent the contact rings and is configured to permit relative rotation between the contact rings and the housing about the common axis. A plurality of contact brushes each have a proximal end connected to means mounted to the housing for supporting a circuit. The circuit supporting means may include one or more printed circuit boards (PCBs) or it may be comprised of other circuit supporting structures. A distal end of each of the contact brushes is slidably engaged with a corresponding one of the contact rings. Optionally a signal generating portion of a position encoder may be mounted on the circuit supporting means. The position encoder has a reference portion that is mounted on the contact ring supporting means.